astrophotography 101

This calculator goes beyond the basic “500 Rule” to determine the best shutter time for non-tracked astrophotography on a fixed tripod. Rather than just focal length, this calculator also factors in the effects of sensor pixel density, declination and allows for an adjustable tolerance for star trailing. Input your camera parameters and the calculator will output a recommended shutter time that minimizes star trailing depending on where you’re pointing your camera in the sky.

ISO is one of the three major exposure settings in the exposure triangle of a digital camera. Of the three: shutter time, f/number, and ISO, it is ISO that is probably most misunderstood. Even more so than f/number. In fact, it is a common misconception that higher ISO settings will cause images to be noisier. In fact, the opposite is often true. Wait, what?

That’s right, higher ISO settings alone do not increase image noise and higher ISOs can even be beneficial to low-light photography. In this post, I talk about the craziness surrounding ISO settings, how ISO actually affects exposure and how to find the optimal ISO setting on your camera for astrophotography.